Means for conditioning air



Feb. 16, 1943. M EN 2,311,583

MEANS FOR CONDITIONING AIR Filed July 12, 1959 mven'rqu N\LS OLOF HARRYSTYREN RTTQRMYS Patented Feb; 16, 1943 MEANS FOR CONDITIONING AIR Nils0101' Harry Styrn, Enkoplng, Sweden, as-

signor to Aktlebolaget Enkiipings Verkstider, Fanna, Enkoping, SwedenApplication July 12, 1939, Serial No. 283,950 In .Sweden June 3, 1938Claims.

This invention refers to means for conditioning air, and it is an objectto perform this with greater efficiency and economy than heretofore, bymeans of a compact installation representing a minimum first cost, whileensuring that the finally conditioned air will be delivered pure andfree from dust and all extraneous odors.

By air conditioning in a wide sense such measures are understood as aretaken to purify the air and to give the same a certain desiredtemperature and relative humidity before the air thus treated isconveyed to the place of use. Such conditioning of the air involvescertain difilculties in cold weather when the low heat content of theouter air presents the danger of forming ice upon the introduction ofthe air into the conditioning apparatus. An object of the invention isto provide such apparatus for conditioning air which may be usedindependently of whatever temperature or humidity the entering raw airmay have, and the apparatus must of course for practical reasons be ofsuch construction that it will always work according to the samefundamental principle notwithstanding changes in the weather.

It has already been suggested to use for air conditioning a rotary drumarranged in a housing, the circumference of said drum being dressed withor made from a filter material, the lower portion of the drum during therotation dipping into a water bath in the bottom of the housing, whilean air current is forced through the filter surface of the drum. Duringthe rotation of this drum, water is taken up by the filter surface, andthe intention is that the air current forced through the filter surfaceshould take up moisture from the water deposited on the filter surfaceat the same time as the air is filtered and also heated, by the waterbath being heated to a suitable temperature. That known apparatus wasalso intended to be used for cooling warm air in summer time, the waterbath then instead being cooled by separate cooling means.

The apparatus embodying the invention includes such a rotary drumarranged within a housing, which drum is provided with filter surfacesthat during the rotation dip into a heated water bath in the lower partof the housing so that the filter surfaces take up water, an air currentbeing pressed through the moistened filter surfaces to be filtered, andthen heated and moistened.

Due to the nature of the filter surfaces heretofore used in suchapparatus, and particularly because of the relatively low heatconductivity of the water, the transmission of heat occurring betweenwater and air is relatively slow. It has therefore been very difllcultto obtain a correctly regulated moistening of the air simultaneouslywith a rapid passage of the latter through the filter material. Thesedifllculties will, of course, increase the colder and drier the incomingair happens to be, in which case a considerable quantity of heat willhave to be transmitted to the air and the necessary moisture added aswell.

According to the present invention these difficulties are avoided bymaking the filter material from metal, the mass of which is so adaptedand distributed in relation to the quantity of water taken up by thefilter material during its passage through the water bath that the majorpart of the heat transmitted to the air is carried by the heatedmetallic masses of the filter, whereas only the remaining minor part ofsaid heat is transmitted to the air by the water taken up by the filterfrom the water bath.

A practical embodiment of the filter material of the drum, having provedto be particularly suitable in actual tests preferably consists of oneor more layers of perforated sheet metal, in which the perforations havebeen made in such a manner that pressed out tongues are formed in thecircumference, which tongues are adapted to act as turbine blades and torotate the drum by the action of the air current blown against thefilter surface. One or more layers of metal wire cloth may, if desiredbe combined with said sheet metal plate or plates for the purpose ofincreasing the heat exchanging ability of the peripheral wall of thedrum. Another embodiment may consist of superposed metal screens.

One form of the filter material and the general arrangement of theapparatus are illustrated on the accompanying drawing forming parthereof, and in the same:

Figs. 1 and 2 show two elevational sections which are perpendicular toeach other, of 'a practical form of an apparatus made according to theinvention and embodying the salient features thereof.

In the practice of my invention a housing I has a lower closed portion 2containing a water bath 3, the level of which is kept constant by meansof an overflow pipe 4 that may be adjustable in height if desired. Thewater is admitted through a suitable inlet controlled by a float 5 sothat the smallest possible quantity of water may flow off through thepipe 4.

Above the water in the housing a hollow cylindrical drum 6 is secured ona rotatable horizontal shaft 1, while its circumference 8 is constructedto form a filter surface consisting, for example of one or severallayers of metal wire cloth having its openings or meshes adapted forfilter action.

At the bottom of the housing, the lower portion of the drum 6 dips intothe water bath 3, while at the top is an intake port 9 for introducingthe air to be treated and ill a rear discharge port for discharging thesame, said intake and discharge ports being so arranged that the airmust pass through the filter surface portion 8 to reach the dischargeport I0. Either the intake port 9 may be connected to the pressure sideof a fan, or the discharge port may be connected to the suction side ofa fan. The intake port 9 is so arranged and directed in relation to thecircumference 8 of the drum that the air current entering the intakeport is urged towards the circumference of the wall, developing forcesthat act so as to turn the drum, whereas the discharge port it isaxially arranged in substantially parallel relation to the shaft of thedrum. The intake port is thus suitably arranged and directed that themajor part of the air is blown tangentially against the circumference ofthe drum. In other words, the air intake port 9 is directed towards theportion of the drum situated above the shaft 1, the upper wall ll of theair intake being arranged at a distance above the circumference of thedrum and curved about the latter so'that a curved channel I! for the airis formed behind the upper portion of the drum, through which channelthe air is led tangentially against the circumference 8 of the latter.

To increase the turning moment caused by the air current impinging onthe drum, a set of plates i3 acting as turbine blades are secured to thedrum inside the circumference 8. These blades 13 are supported by oneend wall H of the drum and extend axially through the drum towards theopposite end wall IS in which an opening I6 is provided for thedischarge of the air.

When the filter surface portion 8 of the drum is made from perforatedsheet metal, the perforations may readily be so punched out that pressedout tongues I I are formed in the filter surface itself which will serveas turbine blades, as indicated in Fig. 1. Said tongues act at the sametime as dust separating elements, as the dust particles, due to theirmomentum tend to rush past the perforations whereas the air is led intothem. It is clear that the blades l3 may be used at the same time. Whenusing perforated sheet metal with such pressed out tongues I 1, one orseveral layers of metal wire cloth may, if desired, be secured inside oroutside the tongues, but this is optional.

The filter drum has been shown as freely rotatably joumalled so as to berotated by the air current blown by a fan, but it should be observedthat the drum may instead be mechanically driven by a separate motor orfrom the shaft that drives the fan when the latter is used, althoughneither are shown. The air to be treated may then of course also be ledthrough the drum either from the inside or the outside, and the drum mayeither be driven in or against the direction of the air currentgenerated by the fan.

While the form of the invention has been described in which the enteringair is to be heated and moistened, it should be clear, however, that thefeatures of the invention are equally well useful in an opposite manneror when the entering air is so warm that it must be cooled instead and,perhaps also deprived of moisture. In such a case the element [8 inFigs. 1 and 2 is instead connected to a cooling plant so that the air iscooled when passing through the filter drum. Any surplus of moisturepresent in the air is then condensed at this lower temperature so thatthe air finally obtains the desired relative humidity in the subsequentfinal heating step, if required.

The air entering through the intake of the housing may consist entirelyof raw air taken directly from the atmosphere, or it may instead consistof return air or be mixed with some return air from the place of airconsumption, if this is desired. If the treatment described is to becombined with a limited dry-heating of the air, such heating can well becarried out by suitable means before the air is led into the housing ofthe invention.

Having now particularly described the nature of my invention and themanner of its operation, what I claim is:

1. In apparatus for conditioning air, having a housing, a drum rotatablyjournalled in said housing, a water bath in the bottom portion of saidhousing and filter surface portions upon said drum adapted to be dippedinto said water bath during the rotation of said drum and take up watertherefrom, there being means for giving the water bath a desiredtemperature, and means for driving a current of air through themoistened filter surface portion in order to purify, moisten and adjustthe temperature of the treated air, the feature which consists in havingthe filter material of said drum consist of metal in the form of apermeable mass which is so conditioned and distributed that the majorpart of the heat exchanged between the air and the water bath istransmitted by the metallic masses of said filter material while onlythe remaining minor part of said heat is transmitted directly by thewater taken up by the rotating drum from the water bath, the air intakeof said drum being so adapted and directed in relation to the drum thatthe air current is blown against the outside of the circumference of thedrum while developing forces that exert a rotating action on the drum,and the air discharge of the drum being arranged axially in relation tothe drum.

2. In apparatus for conditioning air, having a housing, a drum rotatablyjournalled in said housing, a water bath in the bottom portion of saidhousing and filter surface portions upon said drum adapted to be dippedinto said water bath during the rotation of said drum and take up watertherefrom, there being means for giving the water bath a desiredtemperature, and means for driving a current of air through themoistened filter surface portion in order to purify, moisten and adjustthe temperature of the treated air, the feature which consists in havingthe filter material of said drum consist of metal in the form of apermeable mass which is so conditioned and distributed that the majorpart of the heat exchanged between the air and the water bath istransmitted by the metallic masses of said filter material while onlythe remaining minor part of said heat is transmitted directly by thewater taken up by the rotating drum from the water bath, the air intakeof said drum being so adapted and directed in relation to the drum thatthe major part of the air current is blown substantially tangentiallyagainst the circumference of the drum, while developing forces thatexert a rotating action on the drum, and the air discharg of the drumbeing arranged axially in relatlon to the drum.

3. In apparatus for conditioning air, having a housing, a drum rotatablyiournalled in said housing, a water bath in the bottom portion of saidhousing and filter surface portions upon said drum adapted to be dippedinto said water bath during the rotation of said drum and take up watertherefrom, there being means for giving the water bath a desiredtemperature, and means for driving a current of air through themoistened filter surface portion in order to purify, moisten and adjustthe temperature of the treated air, the feature which consists in havingthe filter material of said drum consist of metal in the form of apermeable mass which is so conditioned and distributed that the majorpart of the heat exchanged between the air and the water bath istransmitted by the metallic masses of said filter material while onlythe remaining minor part of said heat is transmitted directly by thewater taken up by the rotating dmm from the water bath, the air intakeof said drum being directed towards the outside of a portion of the drumsituated above the axis of the drum, and the upper wall of the airintake being arranged at a distance above the circumference of the drumand so curved about the latter that a curved channel for the air isformed along the upper and rear part of the drum, through which channelthe air is led tangentially against the circumference of the drum, whiledeveloping forces that exert a rotating action on the drum.

4. In apparatus for conditioning air, having a housing, a drum-rotatab1y Journalled in said housing, a water bath in the bottomportion of said housing and filter surface portions upon said drumadapted to be dipped into'said water bath during the rotation of saiddrum and take up water therefrom, there being means for giving the waterbath a desired temperature, and means tened filter surface portion inorder to purify, moisten and adjust the temperature ofthe treated air,the feature which consists in having the filter material of said'drumconsist of metal in the form of a permeable mass which is so conditionedand distributed that the major part of the heat exchanged between theair and the water bath is transmitted by the metallic masses of fordriving a current of air through the moissaid filter material while onlythe remaining minor part of said heat is transmitted directly by thewater taken up by the rotating drum from the water bath, the air intakeof said drum being so adapted and directed in relation to the drum thatthe air current is blown against the outside of the circumference of thedrum while developing forces that exert a rotating action on the drum,the air discharge of the drum being arranged axially in relation to thedrum, and a set of plates acting as turbine blades being secured to thedrum inside of the circumference so as to aid in the rotation of thedrum by also being actuated by the air current.

5. In apparatus for conditioning air, having a housing, a drum rotatablyjournalled in said housing, a water bath in the bottom portion of saidhousing and filter surface portions upon said drum adapted to be dippedinto said water bath during the rotation of said drum and take up watertherefrom, there being means for giving the water bath a desiredtemperature, and means for driving a current of air through themoistened filter surface portion in order to purify, moisten and adjustthe temperature of the treated air, the feature which consists in havingthe filter material of said drum consist of metal in the form of apermeable mass which is so conditioned and disturbed that the major partof the heat exchanged between the air and the water bath is transmittedby the metallic masses of aid filter material while only the remainingminor part of said heat is transmitted directly by the water taken up bythe rotating drum from the water bath, the air intake of said drum beingso adapted and directed in relation to the drum that the air current isblown against the outside of the circumference of the drum while developing forces that exert a rotating action on the drum, the air dischargeof the drum being arranged axially in relationto the drum, and a set ofplates actingas turbine blades being secured to the drum inside of thecircumference so as to aid in the rotation of the drum by also beingactuated by the air current, said blades being supported by one end wallof the drum and being extended axially through the drum towards theopposite end -vvalle in which a discharge opening for the air isprovided.

NILS OLOF HARRY STYREN.

